Robert S. Pindyck's NBER working paper critiques integrated assessment models (IAMs) used to estimate the social cost of carbon (SCC) and evaluate climate change policies. The paper argues that IAMs are flawed and unreliable for policy analysis due to arbitrary choices in key parameters, such as the discount rate and social welfare function, and lack of theoretical or empirical foundation for their assumptions. The models' descriptions of climate change impacts are ad hoc, and they fail to account for the possibility of catastrophic outcomes, which are critical for understanding the true SCC. The paper highlights that IAMs produce wide variations in SCC estimates based on input assumptions, and that these models are often used to create a false sense of precision and knowledge. The author concludes that IAMs are not useful for evaluating climate change policies and that alternative approaches are needed to better understand the economic impacts of climate change. The paper also emphasizes the importance of considering the possibility of catastrophic outcomes in climate policy decisions.Robert S. Pindyck's NBER working paper critiques integrated assessment models (IAMs) used to estimate the social cost of carbon (SCC) and evaluate climate change policies. The paper argues that IAMs are flawed and unreliable for policy analysis due to arbitrary choices in key parameters, such as the discount rate and social welfare function, and lack of theoretical or empirical foundation for their assumptions. The models' descriptions of climate change impacts are ad hoc, and they fail to account for the possibility of catastrophic outcomes, which are critical for understanding the true SCC. The paper highlights that IAMs produce wide variations in SCC estimates based on input assumptions, and that these models are often used to create a false sense of precision and knowledge. The author concludes that IAMs are not useful for evaluating climate change policies and that alternative approaches are needed to better understand the economic impacts of climate change. The paper also emphasizes the importance of considering the possibility of catastrophic outcomes in climate policy decisions.